Needled fabric and method



Feb. 7, 1961 D. MoRGENsTr-:RN 2,970,365

NEEDLED FABRIC AND METHOD Filed Aug. 4, 195s United States. Parent 10 2,970,365 NEEDLED FABRIC AND METHOD David Morgenstern, 1056 th Ave., New York 28, N.Y.

Filed Aug. 4, 1958, Ser. No. 752,937

9 Claims. (Cl. 28-72.Z)

This invention relates to a new process for manufac- -turing a fibrous sheet material simulating felt, and more particularly to a novel needled fabric and to the method of making same from normally unfeltable fibers.

A prerequisite for making felt by conventional felting techniques is the employment of feltable fibers. Such fibers, including wool, goat hair and other animal fibers, have a substantial curl and even more important a rough surface which allows the fibers to interlock or interfelt into a felt havi-ng substantial strength. Except in admixture with feltable fibers, the vegetable fibers like cotton, the synthetic fibers like rayon, nylon, etc., and even some animal fibers cannot be felted satisfactorily because the characteristically smooth surfaces of these fibers slide upon one another too readily for interfelting. Non-woven fabrics resembling felt can be made from non-felting fibers by needling. In this method a fiber bat -is subjected to many transverse strokes by notched needles which catch fibers during their movement through the thickness of the fleece in one direction, and leave the fibers entangled into a needled fabric. This particular method has the objection that many strokes have to be applied to give some strength to the fabric, and the higher the number of strokes the stiffer the fabric becomes. In order to apply the multitude of strokes needed to give the fabric some strength, the bat or web of heavy fleece has to travel at an extremely low speed, which makes the process very costly.

Needled fabrics suffer from a most serious disadvantage of low strength especially when the fiber bat is not very thick and heavily needled. To avoid this disadvantage many strengthening expedients have been suggested. According to one such method a fibrous fleece is placed fabric.

over one or both surfaces of a woven fabric and subsequently needled, whereby the woven fabric is integrally embedded and made part of the needled felt. The woven fabric supplies strength and stability to the needled felt This method requires a large number of needle 'strokes to combine the fibers with the woven fabric which again stiffens the needled fabric, creates lumps and distortion of the vneedled fabric Iby pushing out inldividual threads during the movement or punching thrust 'ofthe needles, and` increases the cost jof the product. Still another method Vinvolves employment of a poten- 'tiallyfadhesiveresin inhfiber formv as part of the fiber mix, needling, and subsequently heating the rneedled fabric toj atemperature whereat the resinous fibers become `sufliciently tacky Ato adhere tof the V,other bers in the needled fabric.' Y Y.

,Needless t'sayv each of the above` expedients fopform- LingY a" Vsti-long'coherent needled fabric suffers from serious ,disadvantages The principal object of the instant inventionis to`pro vide anovel needled fabric Vof high. strength and dimensional stability. n Y l Another yobjectofthe instant invention4 isvto provide a process for producing a novel needled fabric of high strength and dimensional stability.

Still -a further object of the instant invention 1s Vto provide a process for producing a needled fabric of predetermined thickness, strength and dimensional stability. These and still other objects and advantages will be apparent from the detailed description which follows.

Briefly stated the process of the instant invention con` templates: forming a fleece of fibers, coating the surface with an adhesive binder to form a thin surface layer of bonded fibers, drying said surface and then needling the unbonded fiber fleece through the layer of dried adhesive to form a needled fabric. A single needling operation on each side is suflicient to achieve good felting or interlocking of the fibers, and to create a needled fabric of great softness and drape, yet having considerabl strength and dimensional stability. Although the needling makes multitudinous perforations in the adhesively bonded layer of fibers and actually masks this bonded layer from visual discernment thereof, the integrity of the bonds appears in the final needled As compared to the same fabric made without a surface layer bonded by adhesive, there is substantially increased strength and dimensional `stability depending largely upon the amount and character of the adhesive bond. Moreover, the strength land dimensional stability of the ultimate needled fabric can be predetermined within wide limits according to which of the several preferred modes of the instant invention is employed, and the. amount o-f adhesive employed. By and large, at least 30% of the strength and dimensional stability of the needled fabric is derived from theadhesive, and the balance from the needling action.

For a better understanding of the invention, these preferred embodiments Will be described in connection with the attached drawing wherein:

Figure 1 is a diagrammatic view of a fiber fleece with one surface sprayed with a liquid binder.

Figure 2 is a vertical view of the sprayed fiber lfleecev of Figure 1 after needling.

Figure 3 is a vertical view of two lleeces, each sprayed on one side and plied together with the sprayed surfaces placed facerto face.

Figure 4 shows the two plied fleeces of Figure 3 after needling.

Figure 5 is a vertical view of two plied ileeces both sprayed on each side. Y

Figure 6 is a diagrammatic View of the two plied lleeces of Figure 5 Vduring needling. y f 4 Referring now to Figure 1 of the drawing, there is shown a fiber fleece 7 such as produced by air'deposition or by cards or garnettes. One side or surface of the fleece is shown spray coated with a liquid binder and thereafter dried. Figure 2 shows the same coated fleece 7 after needling. The needling operation has forced individual fibers 3 through the bonded surface layer 6, causing fibers 8 to protrude to the reverse side of layer 6, and in effect form a new outermost surface layer 9, hiding the existence of adhesive bonded layer 6 from visual discernment. v

Numerous variations on the basic invention as illustrated in Figures 1 and 2 are possible. Thus, for example, both surfaces of the initial fleece may be coated with a binder prior to needling. A particularly desirable variation is illustrated in Figures 3 and 4 where two layers of fleece 17, 17, each having an adhesive coated outer Ybels 8 vfrom the upper vlayer H17 into lower layer 17', and a second needling in the opposite direction forces fibers from layer 17 into layer 17 thereby thoroughly interlocking 17, 17' into an integral needled fabric with an adhesively bonded `layer embedded at the center of the needled fabric. As shown in Figures 5 and 6J a thinner spray of binder liquid may advantageously be applied to one or both outer surfaces prior or after needling in order to prevent loose, easily removed fibers from ybeing present on the surface of the ultimate needled fabric. in Figure 6, a pair of needles 11, i2 are diagrammatically illustrated.

For best results, the eece employed for the practice of the instant invention should range in weight between about 0.50 to 7.0 oz. per square yard of single layer. Heavier fabrics than 7 oz. can be built up by employment .of multiple layers in the manner illustrated by Figures 3 4. In contrast, a light but strong needled fabric can be made by needling a single layer of ileece adhesiveily bonded initially on both surfaces.

The eece itself can be composed of any ber: animal, like cattle hair, horse hair, wool, etc.; vegetable, like cotton, linen, plaina, cocoa, etc.; mineral, like asbestos, `glass, metal, etc.; or synthetic, like rayon, acetate, nylon, etc.; or any desired fiber mixture. Although nornfelting bers are most generally contemplated, wool and other felting fibers can be employed.

The binder liquid is also capable of wide variations. ,It may be an aqueous or non-aqueous solution emulsion tor dispersion of adhesive or of latently adhesive material which upon drying or heating forms an adhesive bond. Thus, for example, known adhesives include: rubber (natural and synthetic), vinyl resins, isocyanate resins, ipolyamides, polyacrylates, and others.

' kSuitable solvents lfor the binder liquid include water or organic volatile solvents such as lower alkanols, hydrocarbons, ketones and the like, or mixtures thereof. `iikltern'atively, no `extraneous solvent need by employed when the binder substance is a normally liquid monomer `or polymer which forms a solid adhesive in the course of drying or curing. If desired, a curing agent can be incorporated into the binder liquid to speed up setting of the adhesive during the drying or heating, In ad dition, the binder liquid can incorporate up to 35% by Weight of thermosetting resins such as melamine formaldehyde precondensates for imparting other properties -`as desired. The liquid binder is preferably applied to the eece by spraying through conventional spray nozzles. I However, the binder liquid should not excessively penetrate the liber lieece since the object is to form a thin lsurface layer of bonded bers. To achieve this objective, the eece should be sprayed with that amount of binder liquid which will deposit non-volatile binder solids 'ranging from about 0.05 to 1 times the weight of the jeece.

- The drying and setting of the adhesive binder can 'be accomplished by carrying the sprayed fleece over or between heated rolls with or without the application of pressure, or by carrying the lieece through a drying oven supported otherwise unpress-ured. After drying is com pleted, only the thin layer of fibers affected by the binder are chemically bonded into a thin core or stable 'layer through which free bers from the remainder of the eece are forced by subsequent needling. As has been indicated, one needling operation on each side is suiiicient to achieve a good "felting or interlocking of the tibers, and to create a strong, stable felt with great softness and drape.

The product, either before or after finishing and needling in accordance with the present invention, can be subjected as desired to other treatments such an printing, dyeing, calendering, etc., or the like. if the liquid binder applied is of a thermoplastic nature, the needled yfabric .can be subjected to heat, making the `adhesive `tacky. This `subsequent .treatment will add rmness to 4 .the needled `fabric by bonding the transversely extending bers 8 to layer 6 at the needle perforations of layer 6 where fibers 8 contact the adhesive bonding the original surface layer 6.

The novel process of the present invention is considerably less expensive than felting. A variety of fibers can be used which have no .telting properties, yet the results achieved will be very similar to those of genuine felt, especially as far aS dimensional stability kand strength are concerned. The density of the Vproduct ,made by practice of this invention can be controlled to a greater degree than in .conventional felting or need-ling processes. The same applies to the softness and hand of the fabric as well as air permeability, all of which can be controlled to any desired degree.

Products made in accordance with the practice of the instant invention have an almost unlimited amount of uses in the garment and industrial helds. The products are not intended to merely substitute for existing fabrics. Practice of the instant invention will result in much supcrior products more suitable for certain end uses than textiles now in existence.

The following specic examples further illustrate the practice of the instant invention.

Example I To a single ply `of 4 oz. per sq. yd. cotton ber eee apply on one side 2 oz. per sq. yd. liquid binder the preplasticized polyvinyl chloride emulsion (40% solids con; tent) shown below:

drying, pass the coated iiber fleece lthrough the needling machine with the uncoated side of the eece towards the needles.

Example 1I To a 3 oz. per sq. yd. nylon 'liber iieece apply a ,l oz. per sq. yd. spray Vcoat of a blend of acrylic resin emulsion and casein solution (40% solids) as shown below;

Wet wt.

Acrylic resin emulsion 46% total solids (Rhoplex B-15) 100 Ammonia casein solution 20% total solids 20 Dry the coated iieece two minutes at 250 F. Repeat the l oz. per sq. yd. spray coating on the uncoated Aside After the second coat has been dried, pass the coated fleece through the needling machine twice, turning the piece over between passes.

Example Ill Apply a 1 oz. per sq. yd. spray coat to one side each of two 2 oz. per sq. yd. acetate-nylon blended liber eeces, each eece consisting of 50% acetate staple fiber and 50% nylon staple ber. The spray coating formula is shown below:

40% total solids.

While the sprayed tieeces are wet, they are plied together with the adhesive faces against `each other. Ihe plied eeces are then dried at 250 F. for two minutes,

after-which the plied stock is passed through heated rolls using the following conditions:

Temperature F.-- Gap between rolls inch-- 0.020 Roll surface speed ft. per minute..-

From the rolls, the plied and pressed fleece is passed through the needling machinetwice with the piece being turned over between passes.

Example IV To two 2.5 oz. per sq. yd. wool and nylon blended fleeces apply a 1.5 oz. per sq. yd; spray coat of the compounded nitrile rubber, formulation shown below: Y

Wet wt.

40% total solids.

After spraying, the eeces areplaced against each other so that the binder coated surfaces meet. The plied material is then dried at 250 F. for three minutes. After drying, the plied and bonded fiber fleeces are passed through the needling machine twice. The piece is turned over between passes. The needled piece is now` cure at 275 F. for one hour.

Example V To two 3 oz. per sq. yd. wool fiber iieece apply 1.0 oz. per sq. yd. of polyamide binder of the formula shown below:

- l l Wet wt. Polyamide resin solution 10% total solids (Zytel) 200 Citric acid 1 201 10% total solids.

Place the coated fiber lieeces together in such a manner that the binder coated faces are `against each other. The

plied and bonded fiber fieece is thenoven dried at 250 F. for three minutes. After drying, atop coat of 0.5 oz. per sq. yd. of polyamide binder of the same formulationl used in the first spray operationwis put on vone side 4ofthe bonded fiber fieece. After drying, for one minute at 250 F., the same operation is repeated on the opposite side of the fiber fieece. After drying, the bonded `fiber fleece is passedthrough the needlingmachine twice. 'Ihe piece is turned over between passes. When this operation has been completed, the bonded and plied fiber fleece is oven cured for 10 minutes at 300 F.

Example Vl j v To two 2 oz. per sq. yd'. fiber fleeces of 60% nylon staple fiber and 40% cotton staple fiber, apply a l oz.V

per sq. yd. spray coat of nitrile rubber latex blended with melamine-formaldehyde resin solution as shown in formula below:

40% total solids.

After spraying, -the coated 'fiberl eeces areoven .driedy eeces are plied together' with vthe coated 'sides against each other. This operation is performed' by passing the fleeces through the needling machine twice. The piece is turned over between passes., After needling, the plied,

piece is cured in an ovenV at 2754 F. 'for onerho'ur; i

vJrxzzmplet/II f To two 2.5 oz. per sq. yd.,nylon fiber eeces apply a 1.5;

oz. per sq. yd. spray coat of polyurethane binder using the. formula shown below:

. Wet wt.

Toluene diisocyanate ..f 180 Polyester resin [PPR-4 (Barrett)] 11000 Ethyl acetate f* 590 Toluol p, 590 Methyl diethanolamine` 20 50% total solids.

The coated fberfleece is now plied together with the coated surfaces against Veach other. '1 'he plied liber eece is oven dried at 200 F. for five minutes. After drying, atop coat of 0.5 oz. per sq. yd. of plasticized soya protein binder is sprayed on only one side'of the .fiber fleece. The formula for this top coating is shown belowz'V .Wet wt.

Soya protein 100 Ammonia26 B.' 20 Water J Y. 1489 Polyethylene glycol y '-..'.'--l.....' -22-.. p25

20% total solids. y Y v ,Il

2 After spraying, they plied and coated fiber fleece is dried for one vminute at 250? F. The top coating spray'i and dryingis repeated ongtlie opposte'side of the piece. 'After top coating-,both sides', the :piece is pressed throughl rolls under the conditions shownl below:

WhenY the piece has been rolled, it is passed through the needling machinetwice. The piece is Yturned over between passes through ,the machine. After needling, the bondedv fiber-fleece is cured atl 250 F. forf 20 minutes infan oven. y s

What is claimed isi fleece consisting wholly of loosefibrous (materialhaying adhesive distributed within said loose'fbrous materiali the form of a layer coextensive with and parallel to the planar surfaces of the web, some of the fibers of said web of fibrous material being randomly arranged and some` of the fibers of said fibrous material extending through said adhesive layer and through said web, thelatter fibers extending substantially normal Yto the planar surfaces of said web, said fabric being an integral structure.

2. A needled fabric vcomprising a web of a plurality of fieeces consisting wholly of loose fibrous material, at least one of said tieeces having adhesive distributed within said lose fibrous material in the form of a layer coextensive with and parallel to the planar surfaces of the web, some of the fibers of said web of fibrous material being 'ran-V domly arranged and some of the fibers of said fibrous material extending through said adhesive layer and through said Vweb,the latter fibers extending substantially normal to the planar surfaces of said web and are adhesively bonded to said adhesive layer, said `fabric being an integral structure.

1. A needled fabric `comprising a of a plurality of f square4 yard' comprishga web ofV a pluralityv of vfl'eecrzes. consistingiwholly of loose fibrous` materal' having adhesvedistributed Within said fibrous material in the form ofY a layer coextensiyerwith and parallel to the. planar. surfaces-.of thew'eb andin an amount of lfrom 0.05 to 1.00 times the weight of saidbrous materiaal, some Vof the fibers of said fibrous material being randomly arranged and some of the fibers ofesaidfibrous material extending through said ad-hesive layer and through said web, the latter fibers extending-substantially*normalto the planar surfacesl of said web, said. fabric ybeingan integral'structure. l

4; A needled backing-free fabric comprising a web consisting wholly o-fv loose fibrous material. having adhesive 'distributed-vinthetform ofi a layer coeirtensivewith and parallel-totheplanar surfaces oaf-the web, some of.

the? fibers `of said-fibrousmaterialbeingrandomly ar'.- ranged and-some Vof.v the-fibers ofi said fibrous; material extending through said adhesive layer and through said web;` the latter fibers extending substantially normal to the planar surfaces of said web, said fabric being an integral structure.

e 5. Method of producing aneedledfabric of integral structure which comprises applying to a substantially fiat fleece consisting wholly of loosefibrous material a coatingof liquidadhesive materialthereby bonding some of thesurface fibers ofv the fibrous material to each other to forma thin surface layer of adhesively bonded fibers coextensive with and parallel to the planar surfaces. of the fleece, drying the coating ofadhes'ive material, and then needling said fleece vt'c'form a web whereinsome. of theY fibers of sdfibrous material' are'randomly arranged" and'sonie lof the filiersext'end substantially normal. to the planar surfaces of said web and through the'dry adhesive layer. f. 1 6. Method of producing a needled fabric'of'integral structure which comprises applying tof a1 substantially fiati fleece;` free of fabric backing and consisting-wholly of loose `fibrous mater'ialawcoating of liquid' adhesive material thereby bondin'g some of-V the surface fibers of the fibrous material to each other to. formr athingsurface, layer of adhesively bonded fibers coextensive with and parallel to.. the planar surfaces of t'hefieece, drying the coating of adhesivematerialand V then needling` said fieece to form a web wherein some of the fibers of said fibrous material are randomly arranged and' some of the fibers extend' substantially normalV to the'planar surfaces of lsaidweb and through the dry adhesive layer. 7. Method' of`producing a needled fabric 4of Vintegral structure which comprises applying to. a substantially fiat yfieece-y free of fabric backing and consisting wholly of loose fibrous. material. a coating of liquidv adhesive ma- 'ferial in'an amount of from 0.05 to 1.0 times the weight of" said fibrous material thereby bondingfsomeofjthe, surface fibers of the fib-rous materialL to Veach other to form athinsurfacelayer. of adhesively.. bondediigbers coextensive withv and .parallel.to..the..planan surfacessof the fieece, drying thercoatingaof. adhesive. material; anch then needling,k said fleece to fo-rm a, web wherein, some ofv the, bers of. said` .fibrous material is randomly, arr. ranged and some of the fibers .extend substantially.non mal to the planar surfaces of said web and through the dry adhesive layer.

8. Method ofproducing a-needled; fabric which comprises applying a coatingpf liquid.thermoplasticadhesiye to a surface of at least one of aplurality` of substana. tially fiat iieeces consisting Wholly of loose fibrous mate# rial so thatsome of the surfacefibers4 of the fibrousgrna terial of ythe fieece arerbonded to each other to forni a thin surface layer of adhesively bonded fibers, asserti-V bling the fleecesV with the adhesive-carryingY surface1 of the coated iieece in contact with.another?fieece,4 drying the adhesiva, and then -needling the laminate,- whereby sorne'of the fibers of the fieece are randomly arranged and some of the fibers extend substantially normal to the planar surfaces of the laminate and through the dry adhesive layer to the surfaces of said fieeces, and therrheatf ing the needled laminate whereby` the normally extend-v ing lfibers arebondedto-the adhesive layer. l Y -V i 9. Methodof producing a needled fabric which com prises applying a coating of liquidA adhesive to a surface of atv least one of a plurality of substantially fiat fieeces consistingwholly of loose fibrousmaterial.sovthat some of the surface fibers of the r.fibrous materialiof theiieece are bonded to each other to formua thin surfacel layer of adhesively bonded fibers, assembling the fieeces with the adhesive-carrying surface of the coated fieece in contact` with another fleece, drying the adhesive, and then needling the laminate whereby some-'ofi the fibers of the; fieece are randomly arranged and some of thelfibers extend substantially normal to the planar surfaces of theLla-minate andthrough the dry adhesive la-yep and .then heating-the needledwlaminate whereby-- the normallyi'ex tending fibers are bonded to the adhesive layer.

References Cited in the file of this. patent.

`France Apr. 10, 1933 

